An important part of a SPECT scanner is the collimator. The collimator is used to only transmit gamma rays with certain directions. Behind this collimator is a detector that converts the gamma ray in a measurable signal. Two main types of collimators are known, being the parallel hole collimator and the pinhole collimator. Pinhole collimators are used to select gamma rays from a cone. A pinhole is made out of 2 cones, the top cone is determined by the top of the collimator plate and the aperture and the bottom cone is determined by the aperture and the bottom of the plate. The projection of a pinhole collimator on a flat detector is a circular or elliptical region. Typically, a tradeoff has to be made when using pinholes on rectangular detectors. In case of a single pinhole either detector space will not be irradiated or parts outside the detector will be irradiated. In case of multiple pinholes, the projections of the different pinholes will overlap, or some valuable detector area will not be used. Another solution is to use slats in combination with the collimator to separate the different projections. Such additional shielding typically may result in a significant increase in scattered photons, weight and cost of the system. There is room for improvement of the detection system and/or the collimator component thereof.